News Scan for Apr 13, 2017

Study underscores high rate of severe infections among H5N6 patients

A new analysis of all 17 H5N6 avian flu cases reported in China since 2014 found that 15 out 16 hospitalized patients required mechanical ventilation, while 12 patients (75%) died from their infections.

The case-fatality rate was much lower in patients hospitalized for H5N1 infection (70% or 30 out of 43) and H7N9 infection (41%, or 319 out of 782) during the same period. Patients with confirmed H5N6 were older than those with confirmed H5N1 and H7N9 cases. All H5N6 patients reported close contact with live poultry in the 10 days preceding illness, and they were all located in south and southwest China, compared with wider geographic spread in H5N1 and H7N9 cases.

The analysis was conducted by Chinese officials, the US Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) and published yesterday in Clinical Infectious Diseases.

"The laboratory-confirmed H5N6 cases were characterized by severe illness among the 16 hospitalized cases, with a high risk of fatal outcome," the authors wrote. "It remains to be seen whether HPAI [highly pathogenic avian influenza] H5N6 virus will continue to circulate among poultry and cause sporadic human infections in coming years, as H7N9 virus has done for four years now." Apr 12 Clin Infect Disstudy

Multi-year study notes high death rate in hantavirus pulmonary syndrome

An analysis of more than 600 US cases of hantavirus pulmonary syndrome (HPS) published yesterday in Emerging Infectious Diseases shows a 35% case-fatality rate (CFR) and an especially heavy impact on Native Americans, as well as 2 cases in scientists conducting field work with rodents while not wearing adequate protection.

Hantaviruses are single-stranded RNA viruses in the Bunyaviridae family that cause several disease syndromes, including hemorrhagic fever with renal syndrome and HPS. In the United States, most HPS cases are caused by Sin Nombre virus, which is typically spread to humans via droppings, urine, or saliva of the deer mouse.

For the new study, researchers from the CDC and southwestern health departments probed CDC data from 1993 through 2015, during which 662 lab-confirmed HPS cases were reported, 96% of them in the West. Of all patients, 230 (35%) died, and CFR did not vary by geographic region.

Among the 648 cases for which race was recorded, 78% were white and 18% were Native American. Native American patients were significantly younger than the white patients (34 vs 39 average years old), and their CFR was significantly higher (46% vs 33%).

Rodent exposure was reported for 319 patients, with 228 (71%) reporting home exposure, 102 (32%) occupational exposure, and 78 (24%) recreational exposure. Recreational exposure was more common in the East, but only 17 patients in that region reported rodent exposure. A history of cleaning a probable rodent-infested area was reported for 114 patient (17%), and 49 patients (7%) reported rodent exposure in cars, trailers, or mobile homes.

The investigators also identified two HPS cases that involved lack of adequate personal protective equipment while trapping wild mice for field research studies. They also noted three previous case reports of similar exposure. "Therefore, the use of staff training along with appropriate personal protective equipment in field research settings should be emphasized," they wrote.Apr 12 Emerg Infect Disreport

Meningitis C cases triple in Nigeria as deaths approach 500

Meningitis C cases in Nigeria have topped 4,500, more than triple the count just 3 weeks ago, and 489 related deaths have been confirmed, the WHO said today as it provided details on immunization.

Cases in five states now total 4,637 for the year, up from 1,407 in the WHO's previous update on Mar 24, while deaths have jumped from 201. Meningitis C has been circulating in the country since 2013.

The International Coordinating Group (ICG) on Vaccine Provision has sent 500,000 doses of vaccine containing the "C" strain to Nigeria, the WHO said. The vaccine has been administered in Zamfara and Katsina states, which are the worst affected. An additional 820,000 doses of a meningitis C conjugate vaccine, a donation from the UK government, is being sent.

The ICG has also sent 341,000 vaccine doses to Niger, which has reported more than 1,300 suspected cases of the disease in districts that border Nigeria and in its Niamey region.Apr 13 WHO update Mar 27 CIDRAP News scan on previous update